1. Field of the Invention
The subject invention relates to a type of laser audio-visual equipment, particularly to one which is applicable to two-axle motor rotary mirror reflection system, to upgrade the variation of scanned patterns and visual effects, and to make improvement on such disadvantages of prior arts which patterns could only be projected onto a specified spot and which monotonous variation could not satisfy visual enjoyment.
2. Prior Art
In conventional technology, the two-axle motor rotary mirror reflection system is widely used in bar-code readers, as in the cases of U.S. Pat. No. US515181 and European patent No. UP0412544. A two-axle motor rotary mirror reflection system includes two sets of reflective mirror, each connected to the rotary motor to drive the rotation of the reflective mirror. Meanwhile, each rotary motor is connected to a control circuit to control the rotation of the motor. The light rays coming from the laser light source are reflected through one of its reflective mirrors to become reflected light, then the light rays continue to move forward, then they are reflected at the second reflecting mirror, and finally they become scanned patterns and are projected onto the screen. Such scanned patterns produced from the controlling the motor rotation and the angle of the reflecting mirror are similar to Lissajou pattern, and they would vary with the motor rotation and the angle of the reflecting mirror, and the patterns will vary accordingly. Only trouble is, the variation of such patterns is quite limited and stereotyped.
Referring to FIG. 1 which is the structural view of a prior art of a two-axle motor rotary mirror reflection system. First, a light projecting source 10 is provided, such as a light bulb or a laser source. The light rays projected from the light projecting source 10 are reflected at the first reflecting mirror 11a to produce reflected light, the first reflecting mirror 11a being connected to the first rotating motor 12a, the first rotating motor 12a being electrically connected to the control circuit 13a which serves to control the rotation of the first rotating motor 12a and to drive the first reflecting mirror 11a to rotate. The light rays reflecting from the first reflecting mirror 11a continues to move forward and are reflected at the second reflecting mirror 11b, the second reflecting mirror 11b being connected to the second rotating motor 12b, and the second rotating motor 12b being electrically connected to the control circuit 13b which serves to control the rotation of the second rotating motor 12b, and to drive the second reflecting mirror 11b to rotate. Said device, including the first rotating motor 12a, the first reflecting mirror 11a, the second rotating motor 12b and the second reflecting mirror 11b, constitutes the so-called two-axle motor rotating mirror reflection system, whereby, controlling of the motor rotation and the angle of the reflecting mirror will produce varied scanned patterns similar to Lissajou patterns, such as pattern 15 being projected on the screen 16. Generally, such scanned patterns can only be projected on a specified spot, and its variation is repeated in cycles, so it could not really satisfy our visual enjoyment.
On the other hand, such prior art of two-axle motor rotating mirror reflection system was designed for applications to household or KTV's audio-video recreational purposes. But, such scanned patterns could only have monotonous variations which are repeated again and again, they could not satisfy the visual enjoyment in households or audio-video recreational locations. Therefore, a sound function to control motor rotation has been introduced, in which, as long as there is the existence of sounds, such as music or hand-clapping sounds, it will be able to change motor rotation to enable more variations of the scanned patterns. Though such a method will increase the variations of scanned patterns, such increase is still limited, since the scanned patterns are still repeated and projected onto a specified spot, and it still fails to satisfy the spatial and visual enjoyment that are anticipated in households and audio-video recreational locations.